Spermidine and other functional phytochemicals in soybean seeds: Spatial distribution as visualized by mass spectrometry imaging

Abstract

Soybean seeds contain phytochemicals such as polyamines and isoflavones, which have been identified as functional components mediating health benefits in association with the consumption of soy foods. While a clear picture of the spatial distribution of these components within the seed is lacking, such information would be important to enhance or reduce their concentration in respective foods through processing. Thus, the objective of the present study was to visualize the most relevant components with respect to their distribution in soybean seeds. Mature soybean seeds were subject to atmospheric-pressure scanning-microprobe matrix-assisted laser desorption/ionization (AP-SMALDI) combined with a Fourier-transform orbital trapping mass spectrometer to generate high-resolution chemical images of phytochemical distribution. Based on seed cross sections, differential distributions of functional components were found between soybean cotyledon and germ (shoot, hypocotyl, root) regions. Spermidine and spermine were present in higher concentrations in the germ rather than in cotyledons with highest concentrations in root and shoot meristem tissues. Differential concentrations of spermidine and other components between the germ and cotyledon regions were confirmed by seed fractioning.In contrast to polyamines spermidine and spermine, the different types of daidzein, glycitein, and genistein isoflavones were all visualized in root parenchyma tissue exclusively. Overall, mass spectrometry imaging of soybean seeds revealed clear insights into the differential distribution of functional phytochemicals. Based on their distribution and depending on specific needs, spermidine and isoflavones can either be enriched or reduced during food processing by separating cotyledon and germ fractions. K E Y W O R D SIsoflavones, mass spectrometry imaging, polyamines, soybean, spermidine

Accumulation and Transformation of Biogenic Amines and Gamma-Aminobutyric Acid (GABA) in Chickpea Sourdough

“…High dietary intake of spermidine has been shown to be particularly beneficial in terms of prolonging human life span [57]. The SPD (10.8-11.9 mg/100 g) and SPM (3.1-3.3 mg/100 g) contents of unfermented flours are within the range of the previously reported data on the content in various legumes [58]. The determined SPD content for canned chickpeas is in the range of 8 mg/100 g DW and of SPM 0.5 mg/100 g. This is less than we found for the chickpea flours, which is probably due to the partial dissolution of both polyamines in aqueous media due to their high polarity [56].…”

Fast seed histology protocols: Benzene derivatives-free vs xylene-dependent

“…This research does not pretend to do a detailed histological and cytological description of the seed of the worked species, but to show general anatomical features that support the well working of XD and BDF protocols. All the described features are supported in the literature, reported for other varieties of the worked species, for bean (Recek et al, 2021;Silué et al, 2013), coffee (Amaral da Silva et al, 2004Silva et al, , 2008Araujo Oliveira et al, 2020;Dedecca, 1957), maize (Liu et al, 2013;Rousseau et al, 2015;Tnani, 2012), papaya (Buides et al, 2017;Fresneda et al, 2017;Gil & Miranda, 2011;Mendes de Jesus et al, 2015), rice (Paredes et al, 2021;Ramanadane & Ponnuswamy, 2004), and soybean seed anatomy (Forti et al, 2013;Sagara et al, 2020;Shao et al, 2007;Terán, 2015;Thorne, 2015).…”

Mass spectrometry imaging for direct visualization of components in plants tissues

“…More detailed molecular composition or distribution information were obtained through improving pretreatment, instrumental analysis [95,96] and data processing methods. For example, osmium tetroxide was used to treat the surface of the xylem to oxidize the C=C double bond of coniferin., and spatially differentiation of two substances with close molecular weight, coniferin and sucrose, by detecting the spatial distribution of the oxidized compounds [97] namely multimodal MSI.…”